Filling containers with particulate material

ABSTRACT

A multi-compartment container is charged with a plurality of doses of powdered medicament so that the volume of each dose is than that of the respective compartments in which it is contained. A respective protuberance is inserted into each respective compartment, which is then filled with medicament and the protuberance is then removed. The container may take the form of an apertured plate, in which case the filling step can be achieved by placing the container on a porous bed and in communication with a reservoir of particulate material, and then passing gas through the reservoir, the apertures in the container and the bed. There is also shown apparatus for performing the method, the apparatus comprising a reservoir for the particulate material and a conduit for relaying particulate material from the reservoir to the compartments, the conduit including protuberances which are insertable into the compartments to reduce the available volume of the latter. The size of the doses can be controlled by appropriate selection of protuberance dimensions, and a plate-type container, when filled by the method, can be relatively easily sealed by, for example, the application of laminated foil.

FIELD OF THE INVENTION

This invention relates to a method of and apparatus for introducing eachof a plurality of doses of particulate material into a respectivecompartment of a container. The invention is particularly applicable tothe loading of a multi-compartment container with a powdered medicament.

BACKGROUND OF THE INVENTION

Co-pending PCT Patent Application No PCT/GB94/02716 (Publication NoWO95/16483) describes a method of filling a container such as may beused in an inhaler for dispensing medication for respiratory complaints.In that method, the container, which takes the form of a flexible plate,is laid flat on a porous bed and an excess of powdered medicamentapplied to one face of the plate. Gas pressure is then used to urge themedicament into apertures in the plate, which is then wiped clean of anyexcess of powdered medicament and sealed on opposite faces with laminatefoil so that each aperture of the plate holds a respective individuallyencapsulated dose of medicament.

In this method, the volume of each dose is determined by the capacity ofeach aperture in the plate, and cannot therefore be altered for anygiven container. In addition, residual traces of particulate materialmust be removed from the face of the plate before the foil laminate isapplied, otherwise the effectiveness of the seal between the foil andthe plate may be compromised.

SUMMARY OF THE INVENTION

According to the first aspect of the invention, there is provided amethod of introducing each of a plurality of doses of particulatematerial into a respective compartment of a container, the methodcomprising the steps of:

a) inserting a respective protuberance into each compartment so as toreduce the capacity thereof;

b) filling each compartment with said particulate material, with therespective protuberance inserted in said compartment; and

c) removing said protuberances,

wherein the volume of each dose of material is less than that of itsrespective compartment.

Thus the method enables a container, the compartments of which hithertowould have been completely filled, to hold smaller doses of particulatematerial. This is a particular advantage if the container is for use asan inhaler since containers of the same basic dimensions can then beused to hold doses of medicament which differ in volume.

In addition, if each compartment is completely filled, with aprotuberance inserted, the volume of the resultant dose of material willbe the net of the total volume of the compartment and the volumeoccupied by the protuberance thus, for a given size of compartment, thevolume of the dose can be controlled by selecting a protuberance ofsuitable dimensions.

Preferably, each protuberance comprises a conduit which is insertedpart-way into the respective compartment and through which saidparticulate material is introduced into said compartment.

Preferably, the distance by which each conduit can be inserted into itsrespective compartment is determined by stop means which engage with theportions of the container around the entrance to the compartment toprevent further insertion.

Conveniently, the container may comprise a plate having a plurality ofapertures, each of which constitutes a respective compartment, and inthis case the apertures are preferably filled by the steps ofpositioning the plate on a porous bed with the apertures incommunication with a reservoir of particulate material; applying gaseouspressure to the material in the reservoir so as to transfer particulatematerial from the reservoir to the apertures, the porosity of the bedbeing such as to allow the passage of gas but to prevent the particulatematerial from passing all the way through the apertures and escapingfrom the underside of the plate. Preferably, the gas is passed throughthe porous bed via the reservoir and the apertures.

The use of gas provides additional control over the force with which theparticulate material is urged into the apertures, and hence the densityof the material therein.

Preferably, the bed comprises a perforated base plate and a sheet offinely porous material, for example filter paper, interposed, in use,between the base plate and the container

The apertures, once filled, are preferably sealed so that each dose isindividually encapsulated in its respective aperture, and said sealingis conveniently achieved by bonding a respective sheet of material toeach face of the plate.

Preferably, this is achieved by bonding a sheet of material to theuppermost face of the plate while the plate is supported on a supportfor preventing material escaping from the apertures, inverting theplate, and the support, removing the support to expose the opposite faceof the plate, which is then the uppermost face and bonding a sheet ofmaterial to said opposite face.

Preferably, the support comprises the porous bed.

Since the volume of each dose is less than that of its respectivecompartment, it tends not to stand proud of the upper face of the plateso that the upper face can be kept relatively clear of particulatematerial, thus facilitating bonding of the sheet material. The sameadvantage applies to the sealing of the opposite face since thesubsequent inversion of the plate will allow material to move away fromthat lower face.

Preferably, the sheet material which seals the apertures comprises alaminated foil which is attached to the body by being heat sealedthereto.

The laminated foil tends to resist any tendency for fragments of thesheet to be broken away from the rest of the sheet when the seal for agiven compartment is ruptured to allow material to be discharged fromthat compartment.

The plate may be flexible, in which case the method preferably includesthe steps of rolling or otherwise forming the plate into a cylinder onceit has been filled.

The container may be retained in its cylindrical configuration byapplying an annular end cap thereto, typically two said end caps areused one at each end.

The plate preferably comprises an array of elongated flat, substantiallyrigid strips, adjacent pairs of which are hingeable relative to eachother, such that the strips are substantially parallel to the axis ofthe cylinder in the finished container.

Alternatively, the plate can constitute one of a number of strips whichare fitted together to form a cylindrical composite container.

Preferably, the particulate material is a powdered medicament.

According to a second aspect of the invention, there is providedapparatus for introducing a respective dose of particulate material intoeach of a plurality of compartments of the container, the apparatuscomprising a reservoir for said particulate material, conduit means forconveying particulate material from the reservoir to the compartmentswhen the latter are in registry with the conduit means, and a pluralityof protuberances, each being insertable into a respective compartmenttemporarily to reduce the capacity of the compartment, so that thevolume of each dose is less than that of the compartment in which it iscontained.

Preferably, the protuberances form part of the conduit means, andcomprise a plurality of conduits, each of which is insertable part ofthe way into a respective compartment.

Preferably, the apparatus is arranged to fill a container whichcomprises a plate, in which case, the conduits preferably project from afilling plate which, in use, engages the container to limit the distanceby which the conduits can be inserted into compartments.

BRIEF DESCRIPTION OF THE DRAWINGS

A method and apparatus in accordance with the invention will now bedescribed, by way of example only, with reference to the accompanyingdrawings in which:

FIG. 1 is a plan view of the apparatus which has eight stations,arranged around a carousel, at which various operations are performed;

FIG. 2 is a diagrammatic sectional view, taken in a radial plane and toan enlarged scale, illustrating the activity carried out at the first ofsaid stations;

FIG. 3 is a diagrammatic sectional view, taken in a radial plane and toan enlarged scale, illustrating the activity carried out at the secondof said stations;

FIG. 4 is an exploded sectional side view of two of the components shownin FIG. 3;

FIG. 5 is an exploded isometric view of a filling station, which is thethird station of the device, the Figure also showing the componentstransferred from the second station to the filling station;

FIG. 6 is an exploded radial sectional view of the filling station;

FIGS. 7 to 11 are radial sectional views of the filling station atvarious stages of its operation;

FIGS. 12 to 14 are fragmentary close up sectional views of part of thefilling station and a container, and show the sequence of steps involvedin filling the container;

FIGS. 15 to 19 are radial sections of parts of the fourth station atvarious stages in one cycle of operation;

FIGS. 20 and 21 are similar views illustrating the operations carriedout at the fifth station;

FIG. 22 is a similar view of the sixth station;

FIG. 23 shows parts of the seventh station;

FIG. 24 shows, in radial section, the elements which are transportedfrom the seventh station to the eighth station;

FIGS. 25 and 26 illustrate two of the operations carried out at theeighth station;

FIG. 27 illustrates a plate being rolled into a cylinder.

DETAILED DESCRIPTION

The apparatus shown in the figures is operable to introduce powderedmedicament into the compartments of a container similar to that shown inFIGS. 15A to 15E of published PCT specification No WO95/16483. Theapparatus also seals the container and rolls it into a cylinder for usewith a dispenser of (or similar to) the kind shown in FIGS. 3 to 11 ofWO95/16483.

The container comprises a plate formed from an array of parallel plasticstrips, each of which is hingedly connected to its neighbouring stripsand includes a line of apertures. When the container is rolled into itscylindrical form, all the apertures lie on a helical path.

The number of strips, and the number of apertures in each strip, dependson the number of doses of medicament to be contained in the container.The container shown in the figures has a total of fourteen aperturesarranged in seven strips, each of which has two apertures. However, theapparatus could be modified so as to be capable of filling containershaving different numbers of apertures.

With reference to FIG. 1, the apparatus comprises a carousel 10 andeight stations 1 to 8 positioned around the periphery thereof. In use,the carousel rotates in an anti-clockwise direction to transportcomponents on the carousel to each of the stations in turn, as describedbelow.

FIG. 4 shows a container 12 to be filled and sealed by the apparatus.During the filling sealing of the container 12, it is held within aholder 14, which is shown in more detail in FIG. 5. The holder 14comprises a rectangular frame which is so shaped as to extend around theperiphery of the container 12, and which carries a channel which runsalong the inner periphery of three of the four sides of the frame 14.The fourth side, referenced 16, incorporates an aperture 18 throughwhich the container 12 can be inserted into or removed from the frame14.

When the container 12 is inserted into the frame 14, its edges are heldwithin the channel, so as to locate and retain the container 12 in theframe 14.

With reference to FIG. 2, the frame 14 and the container 12 are carriedon the carousel 10 through the stations 2-4 on a support block 19 whichcarries a perforated metal block 20.

However, before the frame 14 and container are placed on the support 19,the station 8 applies a piece of filter paper 22 to the block 20 asshown in FIG. 2.

To that end, the station 8 includes a head 30 which has a centralpassage 32 which communicates with two feet 34 and 36. The passage 32 isselectably connected to a source of vacuum (not shown), and the head 30is mounted on a pneumatic piston and cylinder assembly 38 which isoperable to raise and lower the head 30. The piston and cylinderassembly 38 is, in turn, suspended from an upper plate 40 (FIG. 1)through drive means (not shown) operable to move the assembly 38, andhence the head 30 radially relative to the carousel 10.

A reel 42 of filter paper is provided at the radial outer end of thestation 8, which includes a punch and die mechanism (not shown) forcutting the filter paper to length.

The head 30. in use, retrieves a cut-out piece of filter paper from theradial outer end of the station 8, a vacuum being applied to the passagein the head to retain the cut-out 22 on the feet, conveys it radiallyinwards to the position shown in FIG. 2, and then lowers the filterpaper 22 onto the block 20. The vacuum is then disconnected so that whenthe head is raised, the filter paper remains on the block 20.

The support is then conveyed on the carousel 10 to the station 1. Thestation 1 has a pneumatic gripper which is mounted on an upper plate 46through a pneumatic piston and cylinder assembly, which is moveablealong the plate 46.

In use, the gripper collects a container, such as the container 14 whichhas been pre-loaded into a frame such as frame 14, from a magazine 52 atthe radial outer end of the station 1, conveys the container and frameto the position shown in FIG. 3 and places them on the support 19 sothat the filter paper 22 is in registry with the container 12. Thegripper is then removed.

The support 19, with the container 12, frame 14 and filter paper 22thereon is then transported to the filling station 2 which is shown inFIGS. 5 to 11.

The filling station 2 comprises a filling head assembly 59 having arectangular inlet manifold 58 which communicates with a pipe 60 throughwhich pressurised nitrogen can be selectively supplied to the manifold.The manifold 58 is sealed against a rectangular upper frame portion 62by an o-ring seal 64 seated in a rectangular groove extending around thetop of the portion 62. The portion 62 includes a central rectangularopening which accommodates a diffuser 66 in the form of a perforatedblock, a peripheral rectangular frame portion 67 surrounds the portion62, and defines, with the portion 62, an inlet aperture whichaccommodates an inlet chute 70, along which powdered medicament issupplied, in use, from an auger 72 via valve 74. The frame portion 67also has an aperture opposite said chute 70 for accommodating anultrasonic level sensor 76. The outer frame portion 67 is sealed againsta lower rectangular frame portion 68 by means of an o-ring seal 65seated in a rectangular peripheral groove extending around the bottom ofthe portion 67. The frame portion 68 includes an aperture in one sidethereof through which a rod 78 extends. The end of the rod is attachedto a rectangular plate 79, the elongate axis of which extendssubstantially perpendicularly to the plane of FIGS. 6 to 11.

A hopper 80 is sealed against the base of the frame portion 68 by ano-ring seal 82 seated in a rectangular groove 84 in the top of thehopper 80. The bottom of the hopper 80 comprises a plate 81, whichincludes a skewed rectangular array of fourteen holes, one of which isdenoted 86, in positions corresponding to the positions of the aperturesin the container 12.

The lower surface of the plate 81 is formed with an array of downwardlyprojecting cylindrical nozzles, for example 88, 92 and 94 (FIGS. 6 to11), each of which is in registry and communicates with a respectiveaperture in the plate 81.

The filling head 59 and container 12 can be lowered from the positionshown in FIG. 7 to that shown in FIG. 8, in which the plate 81 closelyabuts the container 12, the holes in the plate 81 register with theapertures in the container 12, and the nozzles in the plate 81 extendpart way into the apertures in the container 12.

Powdered medicament 90 can be introduced into the hopper through thechute 70. The detector 76 is operable to sense the level of themedicament 90 at the end of the hopper opposite the chute 70, and ifthat level is insufficient, the rod 78 is extended, causing the plate 79to redistribute the medicament 90 over the holes in the plate 81, asshown in FIG. 9.

The container 12 is filled, by introducing nitrogen under pressurethrough the pipe 60. The nitrogen passes through the diffuser 66 (whichprevents the flow of nitrogen adversely affecting the distribution ofthe particulate material 90) through the material 90, the holes andnozzles in the plate 81 and through the apertures in the container 12(FIG. 10). Nitrogen exiting the apertures in the container 12 passesthrough the block 20 via the filter paper 22. This passage of nitrogenurges the powdered medicament 90 through the holes and nozzles in theplate 81 and into the apertures in the container 12. whilst the filterpaper 22 prevents the powdered medicament being expelled through thebottom of the apertures of the container 12.

Three stages during the movement of medicament from the hopper 80 to thecontainer 12 are illustrated in FIGS. 12 to 14. Medicament passes intoeach aperture in the container 12 so that all the available volume ofthe aperture, i.e. the total volume of the aperture minus the volume ofthe nozzle therein, is occupied by the powder, as shown in FIG. 13.

The supply of nitrogen is then interrupted, and the hopper 80, and thefilling head 59 is then raised. When the hopper 80 is not pressurisedwith nitrogen, the powdered medicament in the nozzles forms "bridges"thereacross so that, on raising the filling head 59, the level of powderleft in the apertures in the container 12 is substantially the same asthe level of the bottom of the nozzles, when inserted in the apertures(FIG. 14).

Thus the nozzles allow the apertures in the container 50 to containdoses of medicament which are of a lower volume than that of theapertures. The volume of dose can also be readily adjusted by replacingthe plate 81 with another plate having nozzles of a different height, orapplying packing to the underside of the plate 81 so that the nozzlescannot project so far into the apertures in a container. In addition,the plate 81 can be replaced by another having nozzles, some of whichare higher than the others so as to project further into the container12 than the others. In such an arrangement, some apertures in the plate12 would be provided with larger doses than others.

Once the filling head 59 has been raised from the container 12, as shownin FIG. 11, a further charge of powdered medicament is poured into thehopper for the next filling, and if necessary the powder is levelled bythe plate 79. The filled container 12 and its holder 14 are thentransported by the carousel 10 to the station 3 which includes, at itsradial outer end, a reel 100 of a web 102 of foil laminate (FIGS.15-17), and feed-means (not shown) for feeding foil from the reel past apunch 104 and a die 106, which die defines a rectangular aperture 105(FIG. 15). A sealing head 108 is positionable so that it is in registrywith the aperture defined by the die 106, and is connected to apneumatic piston and cylinder assembly (not shown) which is operable toraise and lower the head 108.

The head 108 includes a heater 110 and a number of feet, one of which isreferenced 112, arranged in a skewed rectangular array on the undersideof the head 108. Each foot is in the form of a short hollow cylinder,the interior of which communicates with a respective vertical passage,for example 114. The vertical passages, in turn, communicate with ahorizontal common passage 116 which is selectively connectable to avacuum source (not shown).

With reference to FIG. 16, the punch 104 is also mounted on a pneumaticpiston cylinder arrangement (not shown) which is operable to raise thepunch 104, causing it to cut from the length of foil 102 a rectangularpiece 118 which is moved up into contact with the head 108. As thishappens, the passage 116 is connected to the vacuum source which causesthe feet on the head 108 to hold the piece 118 thereon.

The web of foil 102 is wider than the cut-out 118, and as a result, whenthe punch 104 is returned to the position shown in FIG. 15, a freshpiece of foil can he drawn into position above the punch 104 by means ofa reel assembly (not shown) positioned to the right of the componentsshown in FIGS. 15 and 16, which is on the opposite side of thosecomponents from the reel 100.

The piston and cylinder attached to the head 108 is mounted on a topplate 120 (FIG. 1) via a drive mechanism for moving the head 108 ineither radial direction. Thus, once the cut-out 118 has been attached tothe head 108, the latter is raised into the position shown in FIG. 17and the drive means operates to move the head radially inwards into theposition shown in FIG. 18, in which it is positioned above the container12, which has been moved on the carousel 10 to the radial inner portionof the station 3.

The head 108 is then lowered onto the container 12 as shown in FIG. 19.The foil laminate of the cut-out 118 has an upper layer (in contact withthe feet on the head 108) which is substantially unaffected by the heatfrom the heater 110. However, the lowermost layer of the laminate ispartially fused by the heat from the heater 108, causing the cut-out 118to be heat-sealed to the container 12. The passage 116 is thendisconnected from the vacuum supply, and the head 108 is raised andreturned to the position shown in FIG. 15, leaving the container 12 witha foil laminate seal on one face.

With reference to FIG. 20, the container 12 and its support 19 are thentransported to the station 4 at which the container 12, the support 19and the block 20 are removed from the carousel 10 and support block 122similar to the block 19, and a solid plate 124, are then placed on topof the container 12 and frame 14. The support blocks 19 and 122 areconnected to a mechanism (not shown) which inverts the elements shown inFIG. 12 in the way indicated by the arrows 126 in FIG. 21 so that thesupport block 19 and perforated block 20 are then uppermost. Thecomponents shown in FIG. 21 are then transported to the station 5 whichincludes a head (not shown) which releasably grips the top of thesupport block 19 and which has a suction mechanism which seals againstthe block 20, to cause the filter paper 22 to be held against the block20. The head is then moved away from the container 12, taking the blocks19 and 20 and the paper 22 with it, as shown in FIG. 22.

The remaining elements shown in FIG. 22 are then transported to thestation 6 which is similar in form and function to the station 8, andwhich thus includes a reel 126 of foil laminate which is fed to a punchand die assembly similar to the punch 104 and die 106.

The punch and die cut out a piece of the foil laminate 130 (FIG. 21),which is then applied to a head 128 of the same kind as the head 108.The head 128 is mounted at the station 8 by a similar arrangement usedto mount the head 108 on the station 3, so that the head 128 can moveradially into the position shown in FIG. 23 in which it is directlyabove the container 12. The head is then lowered, sealing the cut-outpiece of foil laminate 130 to the container 12.

FIG. 24 shows the container 12 in its filled and sealed form, still inits frame 14. In this form, the container 12 and frame 14 are fed to thestation 7 at which the container 12 is removed from the holder 14 androlled into the form of a cylinder in a similar fashion to the methodpreviously described in WO 95/16483.

FIG. 25 shows the container 12 and frame 14 after they have beenseparated (in the station 7) from the block 122 and plate 124, and FIG.26 shows the (filled and sealed) container after having been removedfrom the frame 14. FIGS. 27 and 28 show the plate 124 being formed intoa cylinder 140.

I claim:
 1. A method of introducing each of a plurality of doses ofparticulate material into a respective compartment of a container, thecontainer comprising a plate having a plurality of apertures, each ofwhich constitutes a respective compartment, the method comprising thesteps of:a) inserting a respective protuberance into each compartment soas to reduce the capacity thereof; b) filling each compartment with saidparticulate material, with the respective protuberance inserted in saidcompartment by positioning the plate on a porous bed with the aperturesin communication with a reservoir of particulate material; applyinggaseous pressure to the reservoir so as to transfer particulate materialfrom the reservoir to the apertures, the porosity of the bed being suchas to allow the passage of gas but to prevent the particulate materialfrom passing all the way through the apertures and escaping from theunderside of the plate; and c) removing said protuberances,wherein thevolume of each dose of material is less than that of its respectivecompartment.
 2. A method according to claim 1, in which eachprotuberance comprises a conduit which is inserted part-way into therespective compartment and through which said particulate material isintroduced into said compartment.
 3. A method according to claim 2, inwhich the distance by which each conduit can be inserted into itsrespective compartment is determined by stop means which engage with theportions of the container around the entrance to the compartment toprevent further insertion.
 4. A method according to claim 1, in whichthe application of gaseous pressure involves passing a gas through thereservoir, the apertures and the porous bed.
 5. A method according toclaim 4, in which the bed comprises a perforated base plate and a sheetof finely porous material, for example filter paper, interposed, in use,between the base plate and the container.
 6. A method according to claim5, in which the apertures, once filled, are sealed so that each dose isindividually encapsulated in its respective aperture.
 7. A methodaccording to claim 6, in which said sealing is achieved by bonding arespective sheet of material to each face of the plate.
 8. A methodaccording to claim 7, in which the container is sealed by bonding asheet of material to the uppermost face of the plate while the plate issupported on a support for preventing material escaping from theapertures, inverting the plate, and the support, removing the support toexpose the opposite face of the plate, which is then the uppermost faceand bonding a sheet of material to said opposite face.
 9. A methodaccording to claim 8, in which the support comprises the porous bed. 10.A method according to claim 8, in which the sheet material which sealsthe apertures comprises a laminated foil which is attached to the bodyby being heat sealed thereto.
 11. A method according to claim 10, inwhich the plate is flexible, and the method includes the steps ofrolling or otherwise forming the plate into a cylinder once it has beenfilled.
 12. A method according to claim 11, in which the container isretained in its cylindrical configuration by applying an annular end capthereto.
 13. A method according to claim 11, in which the platecomprises an array of elongated flat, substantially rigid strips,adjacent pairs of which are hingeable relative to each other, such thatthe strips are substantially parallel to the axis of the cylinder in thefinished container.
 14. A method according to claims 1, in which theparticulate material comprises a powdered medicament.